Steam-boiler furnace



no. s||,975. Patented out. 4, lass,

l u.v n.0nvls. STEAMl BUILER FUHNAGE.v

(Application led Apr-.17, 1897. Renewed Har. 9, 1898.)

no. 611,975. Patentednt. 4, |898. ,0. n. onvls.

STEAM BolLl-:n FunnAcE.

(Applicatin led Apr. 17, 1897. Renewed Har. 9, 1898.) (No model.) asheets-snm 2.

@fiend rd,

u. n. onyls. STEAM BUILER FURNACE.

(Application med Apr. 17, 1897. Renewed Mar. 9, 1898.)

Patented Oct. 4, |898.

3' Sheets-Sheet 3.

(No Mndel.)

Nrnn STATES ORLAND D. ORVIS, OF CHICAGO, ILLINOIS.

STEAM-BOILER FURNACE.

SPECIFICATION forming part of Letters Patent No. 611,975, dated October4, 1898. Application iiled April 17,1897. Renewed March 9, 1898. SerialNo. 673,276. (No model.)

,with steam-boilers, without, however, limiting it to thatparticularconnection, and is in the nature of an improvement upon theconstruction of steam-boiler furnaces shown and described in LettersPatent ofthe United States, No.- 524,029, granted to me August '7, 1894.

My present object is to provide certain changes in and additions to thesaid patented construction which, without departing from the generalcharacteristics thereof, render the furnace still more effective in thedirections of perfect combustion of the fuel and maximum utilization ofthe heat for steam production, as well as more economical to constructand easier, quicker, and less expensive to repair.

In the drawings, Figure 1 is a longitudinal section taken on irregularline 1 of Fig. 2, viewed in the direction of the arrow and showing asteam-boiler furnace constructed with my present improvements with oneform of construction at the bridge-wall; Fig. 2, an enlargedcross-section taken on irregular line 2 of Fig. 1 and viewed asindicated by the arrow and showing another form of construction at thebridge-wall; Fig. 3, a broken section on the same scale as Fig. 1, thesection being taken on line 8 of Fig. 2, the construction at thebridge-wall being the same as in Fig. 2; Fig. 4, an enlarged brokensection taken on line 4 of Fig. 3 and viewed inthe direction of thearrow;y Fig. 5, an enlarged section of an arch, taken on line 5 of Fig.1; Fig. 6, a perspective view of one of the blocks or slabs employed inthe arch construction; Fig. 7, a broken section showing one of the sidegrates I employ, and Fig. 8 a section on line 8 of Fig. 7.

A A are the side Walls of thefurnace; B,

the front wall or face; C, the rear wall, and D the bridge-wall.

E is a boiler which may be of any desired construction.

F is the ash-pit, and Gr the fire-chamber. In the ire -chamber G arepreferably two arches H II, extending from the front of the hre-chamberto 4the bridge wall. These arches are of the same form in cross-sectionand are separated by an updraft-passage H. Each arch is formed with twolower tubes or cylinders t t and an upper tube or cylinder t2, supportedat their rear ends in the bridge- Wall and at their forward ends in thefront wall. From the said forward ends, toward the lower sides, extendtubes t3, which project beyond the face of the furnace and are closedwith screw caps or plugs 154. Adjacent to their forward ends the tubesor cylinders t, t', and t2 are provided with upwardly-extending pipes s,which connect with a three-way union s', from which extends a pipe s2 tothe front end of the boiler.

In the construction shown in Fig. 1 the tubes 1527152 extend at theirrear ends to a Water head or chamber H2, mounted in the bridgewall.Extending from the rear ends of the cylinders 'or tubes t, t, and t2, inthe construction shown in Figs. 2, 3, and 4, are pipes r, which connectwith a three-way union r', from which `extends a pipe r2, passingthrough the rear wall C and closed at the end with a removable cap orplug t4. A pipe r3 extends from the pipe rzinto the rear end of theboiler E. In the construction shown in Fig. 1 the pipe r2 communicatesdirectly with the Waterhead H2. The tubes or cylinders t tf form thelower side supports of the respective arch to which they belong, thetube t2 forming the ridge. The body of vthe arch is in sections,comprising blocks or slabs I, of fire-clay or other highly-refractoryheat-storing material. They are preferably of the form shown mostclearly in Figs. 5 and 6, having concave side edges q to t closely overthe tubes or cylinders, against which they rest, and smooth end faces q.The blocks I may be changed in form, as desired; but when placed inposition, as shown, they should iit closely against the front and rearwalls and against each other to form an arch sufciently tight to preventthe passage of any products of combustion except beneath the tubes orcylinders t to the updraft-passage Il.

Resting upon a sill or shelf p at the front wall and upon a sill orshelf p' at the bridgewall are parallel angle-iron su pportin g-beamsp2, the outer edges of which should in praetice be in direct verticalline with the inner edges of the tubes or cylinders t, as shown in Fig.2. Resting in the supports p2 is a plate p3, which extends approximatelythe full length of the supports and :is formed in one piece or ofclosely-fitting sections.

K K are grates extending longitudinally of the supports p2 andpreferably in two sections, as shown in Fig. l, resting at adjacent endson cross-bars a. At the outer edge portions of the grates K areupward-inclined gratescctions, forming side grates K, as shown in Fig.2. The grates K extend in the plane of the plate p3 and are of a widthequal to or nearly equal to the distance between the adjacent sides ofthe cylinders t t', the inclined grates K extending from the edges ofthe grates K to the side walls of the furnace.

In operation the fuel is fed through the door Y and spread over thesurfaces of the grates in a usual manner, the hot products of combustiontherefrom rising under the arches II and escaping beneath the tubes orcylinders tto the ulidraft-passage II', whence they spread under thesurface of the boiler, pass backward over the bridge wall, and thenceforward through the boiler-nues to the chimney-due X. The draft from theashpit to support combustion carries the products of combustion from theburning bed of fuel in the upward direction to till the spaces beneaththe arches, whence, owing to the direction of the draft, they arewhirled downward against or in close proximity to the incandescent bedof fuel. along the inner edges of the grates K, causing approximatelycomplete combustion, all as set forth at length in my aforesaid LettersPatent.

The blocks I, forming the body portions of the arches and having highheat-storing properties,tend when once thoroughly heated to facilitatedecomposition of the products of combustion beneath the arches, and inthe present construction, to aid combustion in the upper portion of thespaces beneath the arches, I prefer wherever practical to providedraft-passages L in the bridge-wall extending from the ash-pit to therear end of the fire-chamber beneath the arches. rlhe draft-passages Lterminate in preferably horizontal narrow elongated openings L, formedin metal plates or blocks set into the bridge-wall, as shown in Fig. 3,the openin gs tapering in the direction of the fire-chamber to increasethe force of the draft, which is thus thrown far forward in thefire-chamber, supplying air to support combustion throughout the upperpart of the spaces beneath the arches. It is found in practice that thedraft-openings L aid materially in effecting complete combustion.

I prefer to construct the bridge-wall of or substantially of thecrescent shape shown, whereby the space between it and the boiler islargest below the center of the latter and becomes gradually reducedtoward the upper end at the sides of the boiler. Thus the greatest draftwill be below the central portion of the boiler instead of at the sides,as is commonly the case, and I have found in practice that I gain verymaterially in steam production by this construction.

The arches, constructed as herein shown and described, are designed tosupersede the water-arches shown and described in my former patent abovereferred to. By preference the arches are given a slight downwardinclination from the front to the rear of the fire-chamber. Thecirculation of water from the boiler is downward through the pipes r3 r2and water-head II2 or pipes r,tl1enee through the tubes or cylinders tt't2, and thence through the pipes-ss2 back to the boiler. IVhere awater-arch comprising a single chamber, as in my aforesaid patent, isemployed, the capacity of the chamber is so much greater than the pipespassing to and from it that the circulation through the chamber isnecessarily slow, whereby over a very hot fire steam may be produced sorapidly therein as to tend to create a back pressure against theinlet-pipes and retard the circulation. In the present construction thetubes or cylinders t t' 2 have all the capacity necessary to cause thewater passing through them to be raised to the desired high temperatureand effect rapid circulation without danger of creating a back pressureagainst the water entering at the pipes r2. The pipes o', employed inthe construction in Figs. 2, 3, and 4, and the tubes 3 join thecylinders near the lower sides of the latter. By removing the screw capsor plugs t* brushes or Scrapers may be readily inserted and passed alongthe base portions of the cylinders and through the pipes to clean themwhen desired.

By employing the supports p2 and plate p3 I dispense with a center wallin the ash-pit, which would not only increase the expense ofconstruction, but also interfere more or less with the air-currents inthe ash-pit.

The inclined side grates K prevent the undue accumulation of fuel alongthe outer edges of the grates, their tendency being to cause the fuel asit is fed to roll or slide toward the center. Furthermore, they tend toproduce a more or less horizontal side draft which stirs up the productsof combustion in a way to greatly Afacilitate combustion.

The plate p3 and its supports p2 operate as a draft-defleetor to preventair-currents from entering the updraft-passage without lirst rising inthe spaces beneath the arches. As before stated, to effect the bestresults the IOO IIO

dellector should be of a width not less than the distance between theinner vertical lines of the adjacent edges of the arches. By supportingthe delector, as stated, the central wall usually provided in theash-pit is dispensed with. This wall not onlyl adds to the cost ofconstruction, but by separating the currents entering the furnace tosupply combustion it is apt to render the currents which llow to the twogrates, respectively, unequal in volume, thereby causing unequalcombustion. In my improved construction the detlector has a clear spacebeneath it for the circulation of air throughout the ash pit, wherebythe objection to the presence of the wall is overcome.

The arches H, constructed as described, are a very desirableimprovement. The tubes t t t2 form circulating-conduits which are alwaysfilled with water and practically indestructible, being rendered so moreespecially by providing them, first, of a' capacity not too great topermit the water heated or steam generated therein to pass readilythrough the pipes s2 to the boiler, and, second,'by inclining them, asdescribed, whereby the tendency of the current under the pressuregenerated in the tubes will be in one direction to maintain a constantcirculation. The blocks or sections I, forming the body portions of thearches, store the heat and tend to neutralize the chilling effectproduced by the circulating-tubes upon the hot products of combustionwhich rise under the arches. Then it is desired for any reason toreplace any of the sections with new ones, this may be done quickly andeasily without disturbing the tubes or the other sections.

I do not limit my invention to the employment of two arches, and, ifdesired, two, only one, or more than three tubes may be provided in thearch to effect the desired circulation. I prefer, however, to employ twoarches of the form shown, each constructed with three tubes orwater-conduits, mounted as stated, and capable with their pipeconnections of maintaining a circulation of suflicient volume andrapidity through the boiler to prevent deposits, and consequentformation of scale, upon the'boiler sheet and liues.

I do not confine my invention to use in connection with asteam-generator, nor when so employed to any particular form ofgenerator, and while I prefer to construct my improvements throughout asshown and described they may be variously modified Without departingfrom the spirit of my invention as defined by the claims.

What I claim as new, and desire to secure by Letters Patent, is-

l. In a boiler-furnace, the combination of a grate, an arch incliningdownward in the backward direction and spanning said grate, and adischarge-passage at one side only of said arch and in a plane betweenthe lower edge of the arch and upper surface of said grate, the archbeing formed of a frame, comrisinO lon 0itudinall extending water cirpt7 E) D culating tubes in communication at opposite ends with theboiler, and a body portion of refractory materialsupported upon theframe and lling out the space between said tubes, substantially asdescribed.

2. VIn a boiler-furnace, the combination of two grate-surfaces separatedby a close longitudinally-extending bed, an arch spanning each of saidgrate-surfaces, an updraft-passage between the arches above said bed,discharge-passages at the adjacent sides of said arches only leading tothe updraft-passage, the arches being formed of frames, comprisinglongitudinally-extending water-circulating tubes in communication atopposite ends with the boiler, and body portions of refractory materialsupported upon the frames and filling out the spaces between the tubes,substantially as described.

3. In a boiler-furnace, the combination of two grate-surfaces separatedby a close longitudinally-extending bed, an arch spanning each of saidgrate-surfaces, an updraft-paspage between the arches above said bed,discharge-passages at the adjacent sides of said arches only leading tothe updraft-passage, the arches being formed of frames, having parallellongitudinally-extending water-circulating tubes, tt t2, inclineddownward in the backward direction, and in communication at oppositeends with the boiler, and body portions of refractory material supportedupon the frames and filling out Vthe spaces between the tubes,substantially as described.

4. In afurnace, the combination of an arch, comprisinglongitudinally-extending watercirculating conduits and a body portionformed of sections of refractory material fitting against and supportedby the conduits, a grate-surface spanned by said arch, and adischarge-passage at one side only of said arch and in a plane betweenthe lower edge of the arch and said grate-surface, substantially as andfor the purpose set forth.

5. In a furnace, the combination with the ash-pit and two parallelcompanion arches separated by an updraft-passage and having outlets attheir adjacent lower sides only communicating with said passage, ofagrate below each said arch and spanned thereby, and a draft-deflectorbetween the grates centrally beneath said passage and extendinglongitudinally above the ash-pit, the deector being supported to leavean open-air circulatingspace beneath it, and being of a width not lessthan the distance between the inner lines of the adjacent edges of thearches, substantially as and for the purpose set forth.

6. In afurnace, the combination of an arch, closed at the rear end,agrate-surface spanned by said arch, a discharge-passage at one side IOOIIO

IZO

only of said arch andin a plane between the lower edge of the archandpsaid grate-surface, a feed-opening,` for fuel at the front end ofthe space covered by the arch, and a draftopening at the rear end of thesaid space above the plane of the said discharge-pas- Sage,substantially as and for the purpose setforth.

7. In a boilerfurnace,tlie combination with a horizontally-disposedcylindrical boiler, of a fire-chamber below one end portion of the 1oboiler, and a bridge-Wall at the end of said iirewehamber, ofsubstantially crescent shape at its upper edge, whereby it extends belowand up opposite sides of the boiler, and the space between it and theboiler is largest be- 10W the center portion of the boiler, substzm- 15tially as and for the purpose set forth.

ORLAND D. ORVIS. In presence of- J. H. LEE, R. T. SPENCER.

